I am seeing some early reports of a Google Toolbar PageRank update this morning. There are threads with discussion on the topic at DigitalPoint Forums and Google Webmaster Help. Plus if you search for [pagerank] on Twitter, you will see lots of people saying their site's PageRank has been updated.
There is currently no thread at WebmasterWorld, but I suspect one to pop up some time this morning.
Again, toolbar PageRank has no direct influence on your search rankings. This is all about egos and making one feel happy or sad. So don't take the update too personally.
Hat tip Colin McDermott...